CODEWITHSUNDEEP
c#wpfdatetimebinding
D. Reagan
D. Reagan

Reputation: 1092

TwoWay Binding a DateTime To a TextBox - Year only

How can I bind (TwoWay) a DateTime to a TextBox such that only the Year of the DateTime is displayed and the TextBox accepts input as a Year as well (i.e. User can type "2014" and this will bind successfully to the DateTime)?

I have the following:

TextBox Margin="10, 1" MinWidth="100" Text="{Binding LastGoodDate, StringFormat={}{0:yyyy}}" >

Which successfully shows the DateTime in yyyy format, however the binding fails when the user types "2014".

I can get around this by binding instead to an intermediate string property, and then manually parsing the result and storing it in the DateTime, but I would like to avoid this if possible.

Any ideas?

Upvotes: 2

Views: 1462

Answers (1)

McGarnagle
McGarnagle

Reputation: 102753

It's probably easiest to do this in the view-model, by adding a separate "Year" property. Eg:

TextBox Text="{Binding LastGoodYear}" >

The property should not have its own backing field, but should modify the date as needed:

public int LastGoodYear
{
    get 
    {
        return LastGoodDate.Year; 
    }
    set
    {
        LastGoodDate = new DateTime(value, LastGoodDate.Month, LastGoodDate.Day);
    }
}

Also make sure to trigger "PropertyChanged" (LastGoodYear) in the "LastGoodDate" setter.

Upvotes: 3

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